From: Christian Brauner <brauner@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org,
Linus Torvalds <torvalds@linux-foundation.org>,
linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org,
Miklos Szeredi <miklos@szeredi.hu>,
linux-cifs@vger.kernel.org
Subject: Re: [PATCH 08/13] nfs: fix UAF on pathwalk running into umount
Date: Mon, 5 Feb 2024 13:29:49 +0100 [thread overview]
Message-ID: <20240205-zieht-zeremonie-8515b74f4d3c@brauner> (raw)
In-Reply-To: <20240204021739.1157830-8-viro@zeniv.linux.org.uk>
On Sun, Feb 04, 2024 at 02:17:34AM +0000, Al Viro wrote:
> NFS ->d_revalidate(), ->permission() and ->get_link() need to access
> some parts of nfs_server when called in RCU mode:
> server->flags
> server->caps
> *(server->io_stats)
> and, worst of all, call
> server->nfs_client->rpc_ops->have_delegation
> (the last one - as NFS_PROTO(inode)->have_delegation()). We really
> don't want to RCU-delay the entire nfs_free_server() (it would have
> to be done with schedule_work() from RCU callback, since it can't
> be made to run from interrupt context), but actual freeing of
> nfs_server and ->io_stats can be done via call_rcu() just fine.
> nfs_client part is handled simply by making nfs_free_client() use
> kfree_rcu().
>
> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
> ---
Acked-by: Christian Brauner <brauner@kernel.org>
next prev parent reply other threads:[~2024-02-05 12:29 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-04 2:14 [PATCHES] RCU pathwalk race fixes Al Viro
2024-02-04 2:17 ` [PATCH 01/13] fs/super.c: don't drop ->s_user_ns until we free struct super_block itself Al Viro
2024-02-04 2:17 ` [PATCH 02/13] rcu pathwalk: prevent bogus hard errors from may_lookup() Al Viro
2024-02-05 12:26 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 03/13] affs: free affs_sb_info with kfree_rcu() Al Viro
2024-02-05 12:26 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 04/13] exfat: move freeing sbi, upcase table and dropping nls into rcu-delayed helper Al Viro
2024-02-05 12:27 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 05/13] hfsplus: switch to rcu-delayed unloading of nls and freeing ->s_fs_info Al Viro
2024-02-05 12:27 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 06/13] afs: fix __afs_break_callback() / afs_drop_open_mmap() race Al Viro
2024-02-05 12:28 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 07/13] nfs: make nfs_set_verifier() safe for use in RCU pathwalk Al Viro
2024-02-05 12:29 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 08/13] nfs: fix UAF on pathwalk running into umount Al Viro
2024-02-05 12:29 ` Christian Brauner [this message]
2024-02-04 2:17 ` [PATCH 09/13] procfs: move dropping pde and pid from ->evict_inode() to ->free_inode() Al Viro
2024-02-05 12:30 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 10/13] procfs: make freeing proc_fs_info rcu-delayed Al Viro
2024-02-05 12:31 ` Christian Brauner
2024-02-04 2:17 ` [PATCH 11/13] fuse: fix UAF in rcu pathwalks Al Viro
2024-02-05 12:31 ` Christian Brauner
2024-02-05 13:51 ` Miklos Szeredi
2024-03-04 14:36 ` Amir Goldstein
2024-03-05 12:43 ` Miklos Szeredi
2024-03-06 10:18 ` Amir Goldstein
2024-03-06 10:21 ` Miklos Szeredi
2024-02-04 2:17 ` [PATCH 12/13] cifs_get_link(): bail out in unsafe case Al Viro
2024-02-04 2:17 ` [PATCH 13/13] ext4_get_link(): fix breakage in RCU mode Al Viro
2024-02-05 12:24 ` [PATCH 01/13] fs/super.c: don't drop ->s_user_ns until we free struct super_block itself Christian Brauner
2024-02-05 12:36 ` Jeff Layton
2024-02-04 2:27 ` RCU pathwalk audit notes Al Viro
2024-02-05 12:48 ` [PATCHES] RCU pathwalk race fixes Jeff Layton
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